Colleen Hardware Manual version A. Undated, circa 1978. The author is not noted on the document.
This is a early technical document about the hardware of the Atari 800. Much of this document would later be published in various hardware manuals, De Re Atari, and elsewhere.
I have scanned two versions of this document. This is the earlier of the two, which I'm calling Version A. Here's Version B. There may have been earlier or later versions, but if so they are not available online to my knowledge.